Research On Three Phase Two Dimensional Wireless Power Transfer System

Magnetic coupled resonant wireless power transfer(MCR-WPT)has the advantages of anti-interference,strong security and high flexibility.It is widely used in electronic industry,medical industry,new energy industry and other fields.Most of the current research on wireless power transfer system is on single-phase power transfer,which has low robustness to the change of load spatial position and cannot carry out efficient power transfer in the case of misalignment,while multi-phase system can generate a more uniform magnetic field and has better position robustness.This paper studies the threephase two-dimensional MCR-WPT system.In this paper,a three-phase two-dimensional MCR-WPT device based on a curved rectangular coil structure is proposed to address the problem of low utilization of magnetic field in traditional three-phase two-dimensional MCR-WPT systems.Firstly,the main circuit model of the three-phase two-dimensional MCR-WPT system is built,the relationship between the output power and transfer efficiency of the system and the circuit parameters is obtained by employing the fundamental wave analysis method,the compensation strategy of the system is analyzed,and the conditions for the soft-switching inverter under the S-S compensation mode are discussed,and the simulation is carried out to verify.Secondly,the simulation models of two kinds of structures of transmitting coil based on curved rectangle and rectangle are built in Maxwell software,the simulation results of magnetic field around the two structures are analyzed,the mutual inductance between coils of different shapes is deduced,the variation rule of mutual inductance between coils is analyzed,and the output characteristics of the system under the two coupling structures are compared.The magnetic field is controlled by using the current direction control method,which increases the magnetic field utilization,and the misalignment tolerance of the system are improved.Thirdly,in response to the problem of output power changes in different locations,a Buck converter is connected in series before the load with double closed-loop PI controller is adjusted by the duty cycle of the switch tube,and then adjust the output current and voltage,to realize the control of the output power,built the simulation model,to verify the effectiveness of the converter to the output control effect,achieve the expected goal.Finally,a three-phase two-dimensional MCR-WPT system with a rated power of15 W is built as an experimental platform to compare the effects of the two structures of transmitting coil on the output power and transfer efficiency of the overall system.The results show that the new structure system is able to transfer more power for a given input voltage and the overall efficiency of the system is improved compared to the conventional structure.